Is often desirable to mount removable accessories to a firearm. Optics and laser sights improve the user's aim; a light enables the user to illuminate his/her surroundings; a camera enables the user to create a visual record of his/her environment.
Firearms have included handguards for many years to protect the user's hands from a hot barrel and to provide a secure gripping means. The four service rifles adopted by the United States armed forces during the twentieth century, the M1903, the M1 Garand, the M14, and the M16, incorporate handguards which make contact with the barrel at multiple locations. These conventional handguards, contacting the barrel in this manner, can transmit external forces to the barrel, sometimes reducing firearm accuracy.
Although these handguards function as intended, it has been well established in the field of competitive target shooting that rifles with barrels that are isolated or “float” without touching the two handguard ends provide superior shooting accuracy. Furthermore, handguards that do not touch the barrel at the front end of the handguard are less likely to conduct unwanted heat into the handguard.
The M16 rifle is a gas operated rifle adopted by the United States armed forces during the period 1962-63. Many variations have been produced since that time including civilian models for sporting uses such as target shooting competition.
The group of firearms generally considered “M16 style” includes gas operated rifles, carbines and pistols (essentially carbines without shoulder stocks) with common design features including a barrel which attaches with a barrel nut, and a gas tube and gas block which are part of the operating mechanism. More recently, pushrods have replaced gas tubes for some variations. The firearms have many designations including M16A2, AR15, M4, and the larger frame Armalite AR10 and its equivalents, which include a larger barrel, barrel nut, and other parts. The M16, M16A2, AR15, AR10, and M4 are all the same family of rifles all originally equipped with the old style (direct impingement) gas system. All of these rifles are capable of being upgraded to various types of piston gas systems by various manufacturers.
Most M16 style firearms produced have conventional, “non-floating” handguards. More recently there has been an increasing trend to issue floating handguard designs to selected military and law enforcement units.
Handguards designed to float the barrel are marketed by several terms, including “float tubes,” “floating handguards,” and “free float sleeves.” Prior art floating handguard systems for M16 style firearms which have the potential for improved accuracy compared to conventional handguards include designs that mount to a floating handguard barrel nut that secures the barrel to the receiver. These designs do not attach at both ends of the handguard, unlike many conventional handguard designs.
Since the 1980's, development of firearm accessories related to optical, laser, and other rapid-growth technologies has resulted in an expansion of the handguard function to include serving as an interface for these devices.
More recently, secondary optics and gun sights, supplemental insulating handguards (handgrips), sling devices, and removable military standard rails have been proliferating and must be interfaced to the firearm, frequently being attached to a handguard rail by rail clamp devices integrated to the accessory. In addition, threaded holes and inserts in handguards allow accessory devices to be attached with screws. By providing this additional functionality, handguards have evolved to being more generally considered as handguard systems.
Prior handguard systems, although functional, have several important deficiencies:
(a) Some prior floating handguards are attached by a yoke that is locked on the barrel nut. The yoke stretches over time, and cannot be re-tightened once it has stretched beyond the limit of adjustment. Thereafter, the handguard loses its rigidity, which adversely affects the accuracy of optics attached to the handguard.
(b) Some handguards contact the barrel at both ends of the handguard, potentially causing impaired shooting accuracy and increased handguard heating.
(c) Many prior handguards do not have integral military standard Picatinny rails (MIL-STD-1913) or threaded holes, thus limiting their ability to mount accessories.
(d) Other prior art handguards suffer other disadvantages such as inadequate repeatable precision of alignment (which generates shooting inaccuracy), complexity and cost of manufacture, and durability.
It is therefore an object of this invention to provide a handguard system that provides a secure and mechanically strong mounting system for accessories such as optics, laser sights, lights, and cameras to a firearm, and that secures the accessory to the firearm regardless of vibrations from firing of the rifle.